Originally Posted by witeboy07
So I've been enjoying my ultra for the last couple days. Battery seems great. But losing percentages of battery at standby caught my eye. My phone would die when I wouldn't even be using it. So yesterday I found the culprit. Mobile network on all the time kept draining it. I disabled it and enabled wifi at work and home and now the battery lasts for days. Just a quick tip.
Sent from my C6802 using xda app-developers app
In every phone that's the main reason for battery drain on standby.
You could set Stamina mode to disconnect some functions you don't use while the screen is off, and leave on just the one that are vital (for you).
Anyway, another reason could be the signal strength in your area: if it's not strong enough, the battery drains because your smartphone is constantly trying to get the best signal (between 2G, E, 3G, H and H+) for its connections, and that is VERY battery consuming.